FEATURES

24 BITS NO MISSING CODES

SIMULTANEOUS 50Hz AND 60Hz REJECTION

(–90dB MINIMUM)

0.0015% INL

21 BITS EFFECTIVE RESOLUTION

PGA = 1), 19 BITS (PGA = 128)

PGA GAINS FROM 1 TO 128

SINGLE-CYCLE SETTLING

PROGRAMMABLE DATA OUTPUT RATES

EXTERNAL DIFFERENTIAL REFERENCE

OF 0.1V TO 5V

ON-CHIP CALIBRATION

SPI™ COMPATIBLE

2.7V TO 5.25V SUPPLY RANGE

600μW POWER CONSUMPTION

UP TO EIGHT INPUT CHANNELS

UP TO EIGHT DATA I/O

APPLICATIONS

INDUSTRIAL PROCESS CONTROL

LIQUID/GAS CHROMATOGRAPHY

BLOOD ANALYSIS

SMART TRANSMITTERS

PORTABLE INSTRUMENTATION

WEIGHT SCALES

DESCRIPTION

The ADS1242 and ADS1243 are precision, wide dynamic

range, delta-sigma, analog-to-digital (A/D) converters with

24-bit resolution operating from 2.7V to 5.25V supplies.

These delta-sigma, A/D converters provide up to 24 bits of no

missing code performance and effective resolution of 21 bits.

The input channels are multiplexed. Internal buffering can be

selected to provide a very high input impedance for direct

connection to transducers or low-level voltage signals. Burnout

current sources are provided that allow for the detection

of an open or shorted sensor. An 8-bit digital-to-analog

converter (DAC) provides an offset correction with a range of

50% of the FSR (Full-Scale Range).

The Programmable Gain Amplifier (PGA) provides selectable

gains of 1 to 128 with an effective resolution of 19 bits at a gain

of 128. The A/D conversion is accomplished with a second-order

delta-sigma modulator and programmable FIR filter that provides

a simultaneous 50Hz and 60Hz notch. The reference input

is differential and can be used for ratiometric conversion.

The serial interface is SPI compatible. Up to eight bits of data

I/O are also provided that can be used for input or output. The

ADS1242 and ADS1243 are designed for high-resolution

measurement applications in smart transmitters, industrial

process control, weight scales, chromatography, and portable

instrumentation.